A continuously variable transmission (CVT) such as a belt-type continuously variable transmission has been conventionally known, which achieves stepless gear shifting by coupling a primary pulley and a secondary pulley with a metallic belt and changing the width of these pulleys. A vehicle having this belt-type continuously variable transmission mounted thereon includes a vehicle that is forward driven only when a forward clutch provided between the continuously variable transmission and an engine is engaged and is reverse driven only when a reverse brake is engaged. When a shift lever is in a non-drive position (e.g., “N” position), the hydraulic pressure is drained to release the forward clutch and the reverse brake. When the shift lever is operated from the non-drive position to a drive position (e.g., “D” position or “R” position) (hereinafter also referred to as garage shifting), the hydraulic pressure is supplied to the forward clutch to engage the forward clutch or the hydraulic pressure is supplied to the reverse brake to engage the reverse brake. Japanese Patent Laying-Open No. 2007-177832 (Patent Document 1), for example, discloses a technique of suppressing belt slip when such garage shifting is done.
A control apparatus disclosed in Japanese Patent Laying-Open No. 2007-177832 controls a vehicle having a belt-type continuously variable transmission placed at a power transmission path between a power source for running and a driving wheel. This vehicle includes: a hydraulic engaging device capable of switching between a power transmission possible state and a power transmission interrupted state of the power transmission path between the power source for running and the continuously variable transmission; a switching valve for switching, based on a signal hydraulic pressure from a second electromagnetic valve, an oil passage for supplying a hydraulic pressure to the hydraulic engaging device to either a first oil passage for supplying a first hydraulic pressure regulated by a first electromagnetic valve in accordance with a predetermined rule to control a transient engaged state of the hydraulic engaging device or a second oil passage for supplying a second hydraulic pressure to bring the hydraulic engaging device into a completely engaged state; and a gear ratio control valve for controlling, based on the signal hydraulic pressure from the second electromagnetic valve, a hydraulic pressure to an actuator for changing a gear ratio of the continuously variable transmission. At the time of the garage shifting in which the shifting operation from the non-drive position to the drive position is performed, this control apparatus outputs, from the second electromagnetic valve, the signal hydraulic pressure for switching the switching valve to the first oil passage, and supplies the hydraulic pressure to the actuator via the gear ratio control valve such that the continuously variable transmission has a prescribed gear ratio regardless of the signal hydraulic pressure for switching the switching valve to the first oil passage. When the hydraulic pressure of the actuator is not enough at the time of the garage shifting in a state where a belt of the continuously variable transmission is not back to a maximum deceleration position at which the gear ratio is maximized, this control apparatus controls the first electromagnetic valve to temporarily decrease the first hydraulic pressure to be lower than a hydraulic pressure set in accordance with the predetermined rule.
According to the control apparatus disclosed in Japanese Patent Laying-Open No. 2007-177832, when the hydraulic pressure of the actuator for changing the gear ratio is not enough at the time of the garage shifting in the state where the belt of the belt-type continuously variable transmission is not back to the maximum deceleration position at which the gear ratio is maximized, the first electromagnetic valve is controlled to temporarily decrease the first hydraulic pressure, which is supplied to the hydraulic engaging device in order to switch the power transmission path between the power source for running and the continuously variable transmission to the power transmission possible state, to be lower than the hydraulic pressure set in accordance with the predetermined rule. Therefore, output torque of the power source for running input to the continuously variable transmission is decreased, and thus, the belt slip when the garage shifting is done in the state where the belt is not back to the maximum deceleration position is suppressed.    Patent Document 1: Japanese Patent Laying-Open No. 2007-177832